Controlled release preparations for cytotoxic or cytostatic drugs

Abstract

A controlled release preparation comprises an ionic polymer matrix loaded with an active compound, particularly a pharmaceutically active compound such as doxorubicin or other cytotoxic or cytostatic drug, the active compound being complexed with a complexing agent such as a metal ion to modify the release of the active compound from the polymer matrix. The ionic polymer matrix may be provided in the form of microspheres, such as microspheres of crosslinked albumin/dextran sulphate.

We claim: 
     
       1. A controlled release preparation comprising an ionic polymer matrix loaded with a pharmaceutically active compound which is a cytotoxic or cytostatic drug, said pharmaceutically active compound being complexed with a metal ion to slow the release of the active compound from the polymer matrix. 
     
     
       2. A preparation according to claim 1, wherein the ionic polymer matrix is in the form of microspheres. 
     
     
       3. A preparation according to claim 2, wherein the microspheres have a diameter in the size range of 10-200 micron. 
     
     
       4. A preparation according to claim 1, wherein the cytotoxic or cytostatic drug is doxorubicin or daunorubicin. 
     
     
       5. A preparation according to claim 1, wherein the ionic polymer matrix comprises a biodegradable crosslinked albumin/dextran sulphate matrix. 
     
     
       6. A preparation according to claim 1, wherein the metal ion is Fe. 
     
     
       7. A preparation according to claim 1, wherein the ionic polymer matrix is selected from the group consisting of a crosslinked albumin/dextran sulphate matrix and a polystyrene-divinylbenzene based ion exchange resin, and the ionic polymer matrix is loaded with Fe-complexed doxorubicin. 
     
     
       8. A controlled release preparation comprising an ionic polymer matrix loaded with cisplatin, said cisplatin complexed with chitosan to slow the release of the cisplatin from the ionic polymer matrix. 
     
     
       9. A preparation according to claim 8, wherein the ionic polymer matrix is selected from the group consisting of a crosslinked albumin/dextran sulphate matrix and a polystyrene-divinylbenzene based ion exchange resin. 
     
     
       10. A pharmaceutical composition comprising a controlled release preparation according to claim 1 or claim 8, together with a pharmaceutically acceptable carrier and/or diluent. 
     
     
       11. A method of treatment of a human or animal patient, which comprises administration to the patient of a therapeutically effective amount of a controlled release preparation according to claim 1 or claim 8. 
     
     
       12. A method according to claim 11, wherein said controlled release preparation is administered parenterally. 
     
     
       13. A preparation according to claim 3, wherein said microspheres have a diameter in the size range of 20-70 micron. 
     
     
       14. A method according to claim 12, wherein said controlled release preparation is administered intraarterially or intravenously.